Pump for high viscosity fluids



K. S. SHERMAN ETAL PUMP FOR HIGH VISCOSITY FLUIDS Filed Feb. 18, 1965 Dec. 8, 1964 United States Patent lilice 3,169,1@' Patented Dec. 8, 1964 3,160,105 PU FR HIGH VISCGSI'IY FLUIDS Kenneth S. Sherman, Livonia, and Cliord R. Alexander, Taylor Center, Mich., assignors to .lohnstone Pump Co., Inc., Detroit, Mich., a corporation of Michigan Filed Feb. 18, 19'53, Ser. No. 259,070 11 Claims. (Cl. 163-48) The invention relates to pumps and refers more particularly to a double acting pump for high viscosity fluids.

In the past pumps for high viscosity liuids have been single acting. Thus pumps for high viscosity huid have in 'the past been of particularly -low eciency. Further, prior pumps for high viscosity fluids containing material such as a fibrous binder have been highly complicated and expensive.

It is therefore one of the objects of `the present invention to provide an improved pump for high viscosity fluids.

Another object is to provide a double acting high viscossity iiuid pump.

Another object is to provide a high viscosity fluid pump comprising a pump cylinder, a pump piston positioned within said cylinder, motor means for reciprocating the pump piston within the pump cylinder and means operable in conjunction with the piston and cylinder for pumping high viscosity fluid from the pump during movement of the piston within the cylinder in each direction of movement thereof.

Another object is to provide a pump as set forth above wherein the pump piston is stepped to provide a plurality of diameters.

Another object is to provide a pump as set forth above wherein the pump cylinder includes an upper portion and a lower portion and the means for pumping fluid includes a check valve positioned between the upper and lower portions for permitting fluid to liow only from the lower portion to the upper portion.

Another object is to provide a pump as set forth above wherein a chopping check valve is provided in the end of the lower portion of the pump cylinder for permitting uid flow into but not out of the lower portion of the pump cylinder and for chopping fibrous material and the like within the high viscosity fluid.

Another object is to provide a pump as set forth above wherein pump priming structure is provided on said end of the lower portion of the pump cylinder including a priming check valve secured on the end of the pump piston.

Another object is to provide a pump which is simple in construction, economical to manufacture and eliicient in use.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a longitudinal section view of a double acting high viscosity liuid pump constructed in accordance with the invention.

FIGURE 2 is a perspective view of a portion of the pump illustrated in FIGURE 1 taken substantially on the line 2--2 in FIGURE 1.

FIGURE 3 is a cross section vieW 0f the pump illustrated in FIGURE l taken substantially on the line 3 3 in FIGURE 1.

FIGURE 4 is a cross section view of the pump illustrated in FIGURE l taken substantially on the line 4-4 in FIGURE 1.

FIGURE 5 is a cross section view of the pump illustrated in FIGURE l taken substantially on the line 5 5 in FIGURE 1.

With particular reference to the figures of the drawings one embodiment of the present invention will now be. considered in detail.

The double acting high viscosity fluid pump 10 illustrated in FIGURE l comprises a pump cylinder 12 in-v cluding the upper and lower cylinder portions 14 and 16 and the pump piston 18 reciprocally mounted in the cylinder 12 for movement in accordance with the actuation of the air motor 20 which is connected to the piston 18. Pump 10 further includes the pump priming structure 22 at the end 24 of pump cylinder 12.

In operation on an upward stroke of piston 18 within cylinder 12 due to actuation of the pump motor 20 high viscosity fluid from the upper pump chamber 26 is forced out of outlet opening 28 in the upper pump cylinder portion 14 while material is taken into the lower pump chamber 3l) through chopping check valve 32. On the down stroke of piston 18, as shown in FIGURE 1, material from pump chamber 39 is forced into pump chamber 26 through check valve 34 and out of the outlet opening 28 due to the smaller volume of chamber 26 as compared to the volume of chamber 30. At the same time additional material is taken into the priming chamber 36 through priming structure 22.

More specifically the pump motor 20 includes the air cylinder 40 having end plates 42 and 44 sealing the opposite ends thereof. End plate 44 is provided with the opening 46 through which the upper end 48 of piston 18 extends. The opening 46 is sealed by sealing ring 50 in the conventional manner to permit reciprocation of the piston 18.

Motor 2G further includes the motor piston 52 secured to the end 48 of pump piston 18 by convenient means, such as the nut 54. Piston sealing structure 56 is provided to prevent leakage between the ends of the cylinder 40 on actuation of the motor 20.

Motor 2G is actuated in the usual manner by introducing air into one of the chambers S8 and 60 through openings 62 and 64 respectively and exhausting air from the other of the chambers.

The upper portion 14 of the pump cylinder 12 is provided with the outlet opening 28 previously indicated through which material is discharged from the pump on both up and down strokes of the piston 18. The end 66 0f the pump cylinder portion 14 is provided With an enlarged threaded internal diameter 68 providing an internal annular abutment 7). End 72 of the upper portion 14 of cylinder 12 is provided with stepped internal diameters 7d and 76 providing annular abutrnents 78 and 8l) respectively.

The piston sleeve 82 having the radially outwardly extending tlange 84 on one end thereof is positioned in the enlarged diameter portion 68 of end 66 of the upper cylinder portion 14 with the flange 84 abutting the annular abutment 70. A piston O-ring 8d and a sleeve O-ring 88 are provided to seal between the end 48 of the piston 18 and the sleeve 82 and between the sleeve 82 and end 66 of cylinder portion 14. The sleeve S2 is held in position in end 66 of the cylinder portion 14 by means of the sleeve retainer 92 threadedly secured to the end 66 of the cylinder portion 14.

Cylinder portion 16 includes the reduced diameter threaded end portion 94. The lower end 96 of the cylinder portion 16 is provided with stepped internal diameters 98 and lill) and a reduced external diameter 102 providing abutments 104, 10d and 108 respectively.

A bleeder valve including the valve tube 112 and the adjusting screw 114 is provided in the passage 116 communicating with the lower chamber 3l) of the cylinder 12. Bleeder valve 11d functions to bleed air from cylinder 12 during initial pump operation.

An upper check plate 118 is positioned between the end 94 of the lower cylinder portion 16 and the annular abutment 8%), as best shown in FIGURE 2. A cooperating upper check valve 120 including angularly spaced axially extending recesses 122 in one end thereof is reciprocally mounted on the central portion 124 of pump piston 18 and is reciprocally movable between the upper check plate M8 and the annular abutment 7S.

The upper check valve E29 is movable between a lower position wherein chambers 26 and 30 are sealed from each other and an upper position, as shown in FIGURES 1 and 2, wherein communication is permitted between the chambers 26 and 30 through recesses l22. The stroke of check valve 34 is very short whereby the efi'iciency. of the pump lfb will be increased as will be Vconsidered more detail subsequently.

A lower or chopping check valve 32 is slidably mounted on the lower portion 126 of pump piston 1S between the lower check plate 128 and the annular abutment 104'. Check valve 32 is provided with an axially extending annular flange 92 having a short radial extent for chopping fibre in the high viscosity fluid when the valve 32 is in the position shown in FGURE 1. l y

The priming structure y22 includes the ring retainer bushing 130 threadedly received in the end 96 of the portion 16 of cylinder 12 for securing the lower check plate 12S against annular abutment 106, the primer valve 132 and the primer valve plate 134.

In operation it will be understood that the collar 136 secured to the pump cylinder portion 16 of pump Il) is secured to a plate 140 which may be maintained at some positive pressure over a high viscosity fluid, such as heavy calking material and sealers so that the calking material and sealer is always present under a positive but relatively low pressure at the priming structure 22. Such structure is well known in the high viscosity fluid pumping art and `is therefore not considered in detail herein.

The pump piston l is then, for example, moved downward in FIGURE l from an upper position wherein piston 52 ofthe pump motor 2d would be adjacent the upper end plate 42 through an intermediate position, as shown in FIGURE 1, to a lower position wherein the piston 52 of motor 20 is adjacent the end plate 44. During the downward stroke of the pump piston 18 the priming check valve 38 is opened, as illustrated in FIGURE 1, whereby the high viscosity fluid is forced into priming chamber 35 under the positive pressure provided by the plate i4@ and associated apparatus (not shown).

The chopping check valve 32 is closed to seal the lower end of the chamber 38 in the cylinder 12 andat the same 4time chop any fibrous material extending through the valve orifice to provide a seal between the .chopping check valve 32 and lower check plate 12S. `During this movement the check valve 34 is raised, as shown in FIGURE 1, so that the high viscosity fluid in chamber 30 is pumped around check valve 34 and through recesses 122 therein :into chamber 26 of cylinder 12.

It will be particularly noted that, due-to the larger diam- 'eter end 48 and the smaller diameter end 126 of the pump piston 18, during this downward stroke the volume -of chamber 30 is caused to decrease more than the vol- -urne of the chamber 26 increases.

A'ward stroke excess material is forced into chamber 26 Thus during the downand consequently out of the outlet opening 28 of the cylin- `der 12 thus providing a pump output during the downstroke of the piston 18.

On the up stroke of the piston 18, as illustrated in FIG- 'URE 1, the upper check valve 34 Vis caused to seat on the upper check plate 84 whereby chamber 26 is sealed and Also, during the up stroke of the piston 18 the check valve 32 is caused to open and the primer check valve 28 is closed whereby the liuid from the priming chamber 36 tis forced into the lower pump chamber 3l@ in preparation d for a second downward stroke of the piston 13 to start a new cycle of operation of the pump liti.

Thus, it will be seen that in accordance with the invention there is provided a double acting pump for high viscosity fluids which besides being double acting is simple in construction, economical to manufacture and wherein the efficiency may be raised from thirty-five percent for thev usual single action high viscosity fluid pump to eighty-five or ninety-five percent figuring the efficiency as pumping time compared to time of movement of the pumping piston in both directions. the upper and lower check valves increases the over-alli efficiency of the pump of the invention.

Further it will be seen that due to the short stroke off Vthe'check valves and the particular efficiency thereof that the pump disclosed may be used to provide very accurate measuring of materials, such as, for example, particular plastics with or without filling material, such as fibers and setting agents therefor which must be accurately proportioned at time of mixing since setting ofthe plastic materials and setting agents is relatively rapid, after mixing thereof.

While one embodiment of the present invention has been considered in detail other embodiments and modifications thereof are contemplated. It is therefore the intention to include all such embodiments and modifications as are defined by the appended claims within the scope of the invention.

' VJhat we claim as our invention is:

1. A double acting pump for high viscosity fluids havl ing two chambers of equal size therein, 'a piston having large diameter central portion, a relatively smaller diameter portion extending into one of said chambers and a still smaller diameter portion extending into the other of said chambers, motor means operably associated with said piston and cylinder for providing relative reciprocal motion between said piston and cylinder, means positioned between and operable in conjunction with said piston and cylinder for transferring the high viscosity fluid from the other of the chambers of said cylinder to the one chamber on movement of said piston relative to said cylinder in one'direction, means positioned between and operable in conjunction with said piston and cylinder for permitting entry of high viscosity fluid into said other chamber only during movement of the piston in anjopposite direction relative to said cylinder and means? for discharging high viscosity fluid from the one chamber on movement of the piston in either of said directional 2. Structure as set forth in claim 1,'wherein the three I diameters of the piston are related so that the large diameter approaches but is smaller than the internal diameter of `said cylinder and the intermediate diameteriand smallest diameter of the piston are related so thati the volume in said other chamber increases and decreasds by substantially twice the lamount of decrease and increase in volume, respectively, of the one chamber on reciprocation of said piston.

3. Structure as set forth in claim 1, wherein the means for transferring fluid between said chambers comprises an annular check valve sleeved over said piston havingr axially extending angularly spaced recesses in the end thereof adjacent said other chamber and movable in a short stroke axially of the pistonv for sealing between said chambers during movement of said piston in said one direction.

4. Structure as set forth in claim 1 and further including priming structure secured to said cylinder for forcing the high viscosity fluid into said other chamber.

5. Structure as set forthin claim 1, wherein air bleed structure is provided extending through the wall of said Vpump cylinder into said other chamber.

Vvlarge diameter central portion, an intermediate diameter The short stroke ofZ portion extending out of said cylinder throughv one end thereof and a small diameter portion extending out of said cylinder through the other end thereof whereby two chambers of different volume are formed in the opposite ends of the cylinder, a check valve positioned between said cylinder portions for permitting high viscosity fluid to pass only from one of said chambers to the other thereof, a chopping check Valve in said other end of the cylinder for permitting flow of high viscosity uid only into said one chamber, priming structure secured to the cylinder adjacent said chopping check valve for forcing Huid into said one chamber only on movement of said piston in one direction, motor means connected to said piston for reciprocating said piston and means for discharging said high viscosity iluid from said other chamber during movement of the pump piston in both directions on reciprocation thereof.

7. A double acting pump for high viscosity iiuids comprising a pump cylinder having two chambers therein, a piston reciprocally mounted in said cylinder, motor means operably associated with said piston and cylinder for providing relative reciprocal motion between said piston and cylinder, means positioned between and operable in conjunction with said piston and cylinder for transferring the high viscosity uid from one of the chambers of said cylinder to the other on movement of said piston relative to said cylinder in one direction, means positioned between and operable in conjunction with said piston and cylinder for permitting entry of high viscosity fluid into said one chamber only during movement of the piston in an opposite direction relative to said cylinder cromprising a chopping check valve slidably mounted on said piston and having an annular axially extending sealing flange with a relatively short radial dimension and means for discharging high viscosity fluid from the other chamber on movement of the piston in either of said directions.

8. A double acting pump for high viscosity uids comprising a pump cylinder having two chambers therein, a piston reciprocally mounted in said cylinder, motor means operably associated with said piston and cylinder for providing relative reciprocal motion between said piston and cylinder, means positioned between and operable in conjunction with said piston and cylinder for transferring the high viscosity iluid from one of the chambers of said cylinder to the other on movement of said piston relative to said cylinder in one direction, means positioned between and operable in conjunction with said piston and cylinder for permitting entry of high viscosity fluid into said one chamber only during movement of the piston an opposite direction relative to said cylinder, means for discharging high viscosity Huid from the other chamber on movement of the piston in either of said directions, and priming structure secured to said cylinder for forcing the high viscosity fluid into said kone chamber comprising a cylindrical bushing secured to said pump cylinder, an extension of said piston rod extending axially through said bushing and a check valve assembly secured to the end of the piston extension for permiting the high viscosity uid to ow into the priming chamber through the check valve assembly only on movement of the piston in said one direction.

9. A double acting pump for high viscosity Huids comprising a pump cylinder having a substantially uniform inner diameter open at one end and having a discharge orice at the other end, a piston reciprocally mounted within said cylinder having a central portion, a smaller diameter portion extending into said other end of the cylinder and a still smaller diameter portion extending into the one end of the cylinder, a check valve positioned over the one end of the cylinder for preventing discharge of material therefrom on movement of the piston toward the one end of the cylinder and a check valve positioned centrally of the cylinder dividing the cylinder into two chambers for preventing movement of material toward said one end of the cylinder on movement of the piston toward the other end of the cylinder While permitting movement of material toward said other end of the cylinder from said one end of the cylinder on movement of the piston toward said one end of the cylinder.

l0. Structure as set forth in claim 9 and Vfurther including an adjustable air bleed in said cylinder in communication with the chamber at the one end of the cylinder.

11. Structure as set forth in claim 9 and further including priming means secured to the said one end of the cylinder for forcing material into the chamber at said one end of the cylinder on movement of the piston toward said other end of the cylinder.

References Cited in the le of this patent UNITED STATES PATENTS 2,360,139 Johnstone Oct. 10, 1944 2,636,441 woelter Apr. 28, 1953 2,807,277 Bailey et al. Sept. 24, 1957 2,837,898 Ahlstraud .lune l0, 1958 3,018,968 Levey Jan. 30, 1962 

1. A DOUBLE ACTING PUMP FOR HIGH VISCOSITY FLUIDS HAVING TWO CHAMBERS OF EQUAL SIZE THEREIN, A PISTON HAVING A LARGE DIAMETER CENTRAL PORTION, A RELATIVELY SMALLER DIAMETER PORTION EXTENDING INTO ONE OF SAID CHAMBERS AND A STILL SMALLER DIAMETER PORTION EXTENDING INTO THE OTHER OF SAID CHAMBERS, MOTOR MEANS OPERABLY ASSOCIATED WITH SAID PISTON AND CYLINDER FOR PROVIDING RELATIVE RECIPROCAL MOTION BETWEEN SAID PISTON AND CYLINDER, MEANS POSITIONED BETWEEN AND OPERABLE IN CONJUNCTION WITH SAID PISTON AND CYLINDER FOR TRANSFERRING THE HIGH VISCOSITY FLUID FROM THE OTHER OF THE CHAMBERS OF SAID CYLINDER TO THE ONE CHAMBER ON MOVEMENT OF SAID PISTON RELATIVE TO SAID CYLINDER IN ONE DIRECTION, MEANS POSITIONED BETWEEN 